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1.
为了解决吸附速率拟合公式缺乏而解吸经验公式众多的问题,通过替换解吸参数、定性和对比分析各经验公式对煤吸附CO2,N2,CH4吸附速率的适用性,选取4种不同煤质的煤样在0.5,1.0和2.0 MPa下进行定温吸附实验,分析压力和煤质对吸附速率的影响规律。研究结果表明:时间函数式对3种气体在不同压力和煤质下的吸附速率拟合效果最佳;压力和煤质对3种气体吸附速率的影响既存在共性又具有差异性,气体吸附速率与压力符合指数函数关系,与挥发分呈现出二次函数关系,并且压力升高会导致最低吸附速率趋向于较高变质程度煤样;CH4和N2的吸附速率随压力升高而升高,而CO2的吸附速率因煤样而不同,且在同压下,不同气体的最高和最低吸附速率煤样的变质程度也不同。  相似文献   
2.
重金属对人体的显著毒性和难降解的特性,使重金属水体污染成为全球性关注的环境问题。本文综述了重金属废水的危害、来源及常用处理方法,比较了不同类型活性炭处理废水中重金属离子的差异,阐述了不同类型活性炭处理技术的优势和特点,并对今后的重金属废水处理技术研究方向进行了展望。  相似文献   
3.
Drawing from signaling theory, we propose a work passion transfer model where leaders' passion is transmitted to employees through the former's leadership style and is contingent on employees' perceived importance of performance to self-esteem (IPSE). Data from 201 supervisor–employee dyads from the health-care industry show that leaders' harmonious passion led to employees' harmonious passion through charismatic leadership, whereas contingent reward leadership accounted for the transfer of obsessive passion; IPSE did not play a moderating role for either form of passion. Results from a supplementary study further reveal that the link between leadership and employee passion operated through employees' perception of leader passion and that employees' IPSE accentuated for the relationship between perceived leader obsessive passion and employees' obsessive passion. This study advances research in work passion, leadership, and signaling theory and provides important implications for managerial practice.  相似文献   
4.
In this paper, we assert and test the proposition that environmental disclosure (ED) is structured by institutionalised myths and that is why ED is decoupled from environmental performance and media pressures. Focusing on firms from Canada, France and Germany, findings show that ED mimetic isomorphism for different topics varies among countries and by industry sensitiveness to the environment. The results corroborate the institutional presumption that institutionalised myths vary among different contexts. Our findings also suggest that institutionalised ED structures may not reflect environmental performance, mimetic patterns being affected by environmental performance. However, the decoupling between ED mimetic isomorphism and environmental performance decrease when firms’ ED credibility is questioned by the media.  相似文献   
5.
Objective: The present research relies on 2 main objectives. The first is to investigate whether latent model analysis through a structural equation model can be implemented on driving simulator data in order to define an unobserved driving performance variable. Subsequently, the second objective is to investigate and quantify the effect of several risk factors including distraction sources, driver characteristics, and road and traffic environment on the overall driving performance and not in independent driving performance measures.

Methods: For the scope of the present research, 95 participants from all age groups were asked to drive under different types of distraction (conversation with passenger, cell phone use) in urban and rural road environments with low and high traffic volume in a driving simulator experiment. Then, in the framework of the statistical analysis, a correlation table is presented investigating any of a broad class of statistical relationships between driving simulator measures and a structural equation model is developed in which overall driving performance is estimated as a latent variable based on several individual driving simulator measures.

Results: Results confirm the suitability of the structural equation model and indicate that the selection of the specific performance measures that define overall performance should be guided by a rule of representativeness between the selected variables. Moreover, results indicate that conversation with the passenger was not found to have a statistically significant effect, indicating that drivers do not change their performance while conversing with a passenger compared to undistracted driving. On the other hand, results support the hypothesis that cell phone use has a negative effect on driving performance. Furthermore, regarding driver characteristics, age, gender, and experience all have a significant effect on driving performance, indicating that driver-related characteristics play the most crucial role in overall driving performance.

Conclusions: The findings of this study allow a new approach to the investigation of driving behavior in driving simulator experiments and in general. By the successful implementation of the structural equation model, driving behavior can be assessed in terms of overall performance and not through individual performance measures, which allows an important scientific step forward from piecemeal analyses to a sound combined analysis of the interrelationship between several risk factors and overall driving performance.  相似文献   

6.
Abstract

Objective: The objective of this article is to describe the characteristics of fatal crashes with bicyclists on Swedish roads in rural and urban areas and to investigate the potential of bicycle helmets and different vehicle and road infrastructure interventions to prevent them. The study has a comprehensive approach to provide road authorities and vehicle manufacturers with recommendations for future priorities.

Methods: The Swedish Transport Administration’s (STA) in-depth database of fatal crashes was used for case-by-case analysis of fatal cycling accidents (2006–2016) on rural (n?=?82) and urban (n?=?102) roads. The database consists of information from the police, medical journals, autopsy reports, accident analyses performed by STA, and witness statements. The potential of helmet use and various vehicle and road infrastructure safety interventions was determined retrospectively for each case by analyzing the chain of events leading to the fatality. The potential of vehicle safety countermeasures was analyzed based on prognoses on their implementation rates in the Swedish vehicle fleet.

Results: The most common accident scenario on rural roads was that the bicyclist was struck while cycling along the side of the road. On urban roads, the majority of accidents occurred in intersections. Most accidents involved a passenger car, but heavy trucks were also common, especially in urban areas. Most accidents occurred in daylight conditions (73%). Almost half (46%) of nonhelmeted bicyclists would have survived with a helmet. It was assessed that nearly 60% of the fatal accidents could be addressed by advanced vehicle safety technologies, especially autonomous emergency braking with the ability to detect bicyclists. With regard to interventions in the road infrastructure, separated paths for bicyclists and bicycle crossings with speed calming measures were found to have the greatest safety potential. Results indicated that 91% of fatally injured bicyclists could potentially be saved with known techniques. However, it will take a long time for such technologies to be widespread.

Conclusions: The majority of fatally injured bicyclists studied could potentially be saved with known techniques. A speedy implementation of important vehicle safety systems is recommended. A fast introduction of effective interventions in the road infrastructure is also necessary, preferably with a plan for prioritization.  相似文献   
7.
为了解决平视显示器(Head Up Display,HUD)飞行中的注意资源分配问题,基于飞行模拟器,设计双作业飞行任务开展相关研究。基于事件相关电位(Event Related Potential,ERP)技术,选取行为绩效和P300成分为评价指标,采用oddball模式,在双作业飞行任务条件下开展实验研究。结果表明:随主任务难度的增加,主、辅任务的作业绩效均显著下降,被试者对HUD上异常信息的正确操作率降低,且反应时间延长;随主任务难度的增加,由辅任务所诱发的P300的波幅显著降低。在实验结果的基础上,最终提出了HUD状态下飞行员视觉注意资源分配机制。  相似文献   
8.
选用正十六烷模拟润滑油,通过振荡平衡实验,考察了两种含氮脂肪酸型生物降解促进剂(甲基二乙醇胺油酸酯(MDEAO)和油酸二乙醇酰胺(ODEA))对水土体系中正十六烷吸附行为的影响。实验结果表明:正十六烷在水土体系中的有机质标化分配系数与土壤种类无关,与生物降解促进剂种类有关;土壤对正十六烷的吸附过程更符合Freundlich等温吸附模型;MDEAO的临界胶束浓度为2.0 mg/L,对土壤吸附正十六烷有一定的促进作用,ODEA的临界胶束浓度为0.7 mg/L,形成的胶束对正十六烷的增溶效果明显,促进了正十六烷在土壤中的解吸。  相似文献   
9.
采用水浴提取法处理羊八井地热区土壤和植物样品中可溶性氟,并用离子选择性电极法测定提取液及地热水中的氟。结果表明,地热水中氟离子最高为162 mg/L,土壤和植物中水溶性氟分别为347 mg/kg~937 mg/kg和189 mg/kg~164 mg/kg。氟离子在不同植物中的分布差异较大,嵩草属植物富集氟离子的能力最强,故可利用植物修复技术对高氟地热水、土壤净化处理,以降低氟污染。  相似文献   
10.
为明晰大数据对安全绩效管理的影响,把握信息时代下企业安全绩效管理的研究方向,基于大数据时代下安全绩效管理内容,阐述数据驱动下安全绩效管理的应用优势,探讨数据驱动下安全绩效管理的研究变革,剖析大数据环境下企业安全绩效管理的数据流向,构建数据驱动下安全绩效管理的框架模型,并提出数据驱动下企业安全绩效管理应用对策。结果表明:基于大数据的安全绩效管理有助于提升企业安全管理水平,也为安全生产系统优化提供理论依据。  相似文献   
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